Rotary table drive connection



Oct. 7, 1952 c. R. TRAHAN ROTARY TABLE DRIVE CONNECTION 2 SHEETS- SHEET `2 Filed Feb. 15, 1950 C/QUd/e R. Tra/)0n INVENTOR.

A T TOR/VEV Patented ct. 7, 1.952

UNITED STATE S PATENTOFFICE 1 This invention relates to a drive connection for use in rotary drilling and. particularly to an extendible and retractable drive connection between a rotary table and drill rods or pipe extending therethrough into a well.

In conventional rotary drilling, the usual rotary table is provided with a square or other polygonal drivebushing through which the square or polygonal Kelly joint extends, in order to pro-` vide a drive connection between the rotary table and the kelly, for rotating the latter to thereby rotate the pipe string which is connected to the kelly and extends into the well. This arrangement is entirely conventional and presents no serious complications in the ordinary case of initially drilling Aa well.` However. once a well has been completed `'and equipped with usual well head fittings,l itv is often necessary to go back into the well `torre-working andlother op- Y erationswhich require rotation of the pipe or other string carrying a suitable tool which is run into the well for` re-working purposes. In such cases'it'is' often impractical to strip all of the surface connections `and `fittings from thewell head and the rotary table must be placed above these iittings. It would Athen lbe necessary to run thekelly through these fittings and because of its non-round shape, it would be dlfllcult and generallyfirnpractical to employ blow-out preventers or', other sealsvwhich would be effective to seal aboutthenon-round surfacesof the kelly in order" to hold the well under control, while at Vthe same time permitting rotation and Hadvancernent of the kelly.

Accordingly, the` present invention has for'its principal object the provision of a drive connection for connecting the rotary table with a pipe string` extending therethrough, which maybe employed above the well head `fittings, and by means of which the use of a conventional Kelly joint for rotating the pipe may be eliminated.

An important 4object is the provision of a longitudinally extendible and `retractable drive connection extending between the rotary table and the pipe string to be driven thereby. y

A more specific object is the provision of a drive connection embodying a plurality of sections of successively reduced dimensions designed to telescope one within the other for relative extension and retraction, having means preventing relative'rotation between the-sections, and having clamping or gripping elementsconnected to the uppermost and innermost section for grippingmthe pipe to be driven thereby, the

lowermost or outermost section having means e 2 claims. (ci. .c55-aai" I c 2 forming a `drive connection with the rotary table.

,Other and more specificV objects and advantages ofthis invention will become readily apparent from the following detailed description when read in conjunction with the accompany ingl drawings ,which illustrate useful embodimentsin accordance with this invention.

AIn the drawings:

'.lig.A lis an elevational view, showing one form of driveconnection in accordance with this invention installed in driving relation between a rotary table and a drill pipe string of a conventional drilling rig;

Fig', 2 is a longitudinal generally sectional view of the drive connection in extended position as shown inFig..1;, t

Fig. 3 is an enlarged` view in longitudinal sectionillustrating a detail'of construction of the drive connection;

Fig. 4 is a longitudinal sectional view of the drive connection shown in collapsed or retracted position; ,e

, Fig."5` is a top view of thedrive connection lookngdown along line 5---5` of Fig. 4;

Fig.`6`isa transverse cross-sectional view along line 8,-6 of FigA; f

Fig.` 7 is a longitudinal sectional view of a drive connection` in accordance with another embodiment of this invention, shown in' extended posidrawn from a well bore indicated at I4. The; pipe string Il) passes through a conventional rotary table I5 located in the derrick above theI mouth of the well which is drivingly connected to the pipe stringjby means of a collapsible drive connectionlin accordance rwith this invention,4 designated generally by the numeral I6.

Drive connection IB is composed of a plurality of hollow tubular sections I1, which may be of square cross-section, as shown in Figs. l to 6, inclusive, or of other suitable non-round. shape, or may be round as shown in Figs. 7 and 8. Sections I1 are successively smaller in dimensions in ascending order so that each Will telescope within those below it. and the sections are dimensioned so that each will slide freely inside the sub-adjacent one. `The square or other nonround confgurationof the sections form splinetype connections between the sections to prevent relative rotation therebetween while permitting relative longitudinal movement. A

The lowermost and largest of the sections I1 is enlarged at its lower end to form a base I8 having a shape and dimensions such as to form a close sliding fit in the usual square drive bushing socket I9 in rotary table I5 so that when base I8 is seated in the socket it will be rotatively driven by the rotary table. An outwardly extending iiange 20 or similar abutment is mounted on the exterior of the lowermost section II adjacent the upper end of base I8 and is adapted to engage the upper surface of the rotary 4table about socket I9 when the section is seated therein to prevent the base section from slipping downwardly' throughA the rotary table.

Each of the sections I'I, except the uppermost ,f

ZI adjacent its upper end which is adapted to abut with an outwardly extending lug 22 mount-v ed about the lower edge of each of the sections except the lowermost one. By means of lugs 2l and 22 it will be seen that each of the sections is thus prevented from being withdrawn upwardly from the next lower section. The inner and outer dimensions of lugs 2i and 22 are made such that they will be in close sliding engagement with the adjacent surfaces of the inter-engaged sections. rihe width of these lugs in the longitudinal 'dimension will preferably be made such that Substantial areas of the sections will be kengaged y*by the outer faces of the lugs to thereby reduce any tendency of the sections to wobble, particularly when in the fully extended positions. Ordinarily the width of lug 22 will be made greater 'than that of lug 2l but it is obvious that the reverse arrangement may be employed or that the lugs may be of equal Width.

The drive connection is assembled by serially inserting the sections of successively smaller Sdiameter upwardly through the interior of the lowermost section. As each section is inserted through the preceding larger section, a suitable projection means such as lugs '23 will be attached about the exterior of the upper'end of th'e'inserted section (see Fig'. '3) to form anabut'ment which will prevent the inserted sections 'from slipping downwardly vout of the sections iin which they are inserted.

The upper end of the uppermost sectionfll has mounted thereon a segmental clamping means', designated generally by the numeral 24, which may be composed of two complementary s e'micircular segments 24a and 24h, shaped'and dimensioned to enclose pipe iii, and provided with mating ears 25,-25, through which extend bolts it for drawing together the segments about the pipe. mounted inside the segments and are adapted to tightly grip pipe I0 when the clamping means is closed about the pipe.' One of the vsegments 24a-Mb will be permanently connected to the upper end of the section I'I, as byfwe'lding or other suitable connecting means, and the other will be separably connected thereto by mea'nsof boltsZt. The ears 25 extend laterally Vbeyond the 'sides of the section to which they are attached 'and will thereby form abutments engageable with the next lower section I"I 'to prevent the uppermost section from falling downwardly therethrough.

The number of the sections I1 and their lengths may be varied as may be required to meet particular conditions. Normally, 'theywill be made ci approximately equal length so that when the Toothed pipe-gripping kdies 277-27, are' ,4 sections are fully retracted, as shown in Fig. 4, the total length of the drive connection will be approximately that of the lowermost section so that the length of movement between fully extended and fully retracted positions will provide for an appropriate length of longitudinal movement of pipe I0.

The drive connection may be employed in the following manner: The drive connection is installed in socket I9 by inserting base I8 therein. Pipe Ill carrying a drill bit or other tool on its lower end will be inserted through the bore of the connection and lowered into the well to the point at which the Ytool is to begin operation. The drive connection will then be extended to its full length or to any portion thereof, as may be desired, by drawing the uppermost section II bearing clamping means 2li upwardly by means of any suitable hoisting mechanism. Clamping means 24 will then be closed about the pipe, the segments thereof being drawn together byv means of bolts 26 to a sumcient degree of tightness to cause dies 21 to strongly' grip the pipe, thereby completing the drive connection between the pipe and the rotary table. Rotation of the latter will now operate in the usual manner to rotate the pipe and thereby rotatively drive the tool attached thereto.

As pipe Ill moves downwardly with the progress of the tool in the WelLseCtiOns I'I of the drive connection `will be retracted correspondingly and this retractive movement will continue until the drive connection is fully retracted. Thereupon clamping means 24 will be released from the pipe and the drivev connection again extended and reclarnped at a higher point on the pipe and further rotation and downward movement continued for another increment corresponding generally to the length of the drive connection. These operations will be repeated until the tool driven by pipe It 'attains the ultimate depth desired.

By means of the described drive connection, it Will be evident that pipe I0 may be rotated in either direction as may be required without special connections, and that any length of stroke or increment of downward movement may be provided.

Figs. 7 and 8 illustrate another embodiment in accordance with this invention wherein the sections of the drive'connection are generally cylindrical rather than square in cross-section and longitudinal spline connections are'provided between the sections' to prevent relative rotation between the sections. In this embodiment, the telescoping sections lIa are cylindrical and may conveniently be constructed from vlengths of` pipe of successively smaller diameters. The lowermost section is provided with a hollow square base Ia, adapted to nt in the. rotary table socket I9, and a ange 20a for engaging the top of the rotary table. In order to prevent relative rotation between the sections Ila, one or more angularly spaced spline groovesv 30 are cut longitudinally in the exterior wall of each of the sections except the lowermost one and a corresponding number of short spline teethBI are formed or mounted inside the upper ends ofeach of the sections to project into the grooves.- The lower ends of the spline grooves are closed at 32 toform abutments which engageth'elower ends of the spline teeth to prevent upward withdrawal of one section from the otherx rI-he upper ends ofthe spline grooves are open tov receive the teeth when the sections are assembled by the' insertion of one section upwardly through the lower end of Vthe next larger section. After assembly of the sections,

bodiments within the scope of the appended v claims but without departing from the spirit of this invention.

What I claim and desire to secure by Letters Patent is:

1. A drive connection for drivingly connecting a rotary table to a pipe extending therethrough, compri-sing, a plurality oi concentric tubular sections telescopically connected together for longitudinal extension and retraction adapted to surround the pipe, each of the sections except the outermost one, having a plurality of angularly spaced spline grooves in the exterior thereof eX- tending longitudinally from the upper end thereor to points spaced from the lower end thereof to define upwardly facing shoulders at the lower ends oi the grooves, each of the sections except the innermost one having mounted adjacent its upper end inwardly extending lugs projecting into the grooves of the adjacent section for ensagement with said shoulders to thereby limit CII outward relative movement of the adjacent sections, and each of the sections except the outermost one having mounted adjacent its upper end outwardly projecting lug means engageable with the upper end of the next larger section to limit relative inward movement of the adjacent sections, a base member of polygonal shape mounted on the lower end of the outermost section for insertion in a correspondingly shaped socket in a rotary table, an outwardly extending flange about said base member engageable with the y upper end of said rotary table, and relleasable pipe gripping means mounted on the upper end of the innermost section for connection to said pipe.

2. A drive connection according to claim 1 wherein said pipe gripping means comprises a pair of complementary semi-circular segments adapted to be closed about said pipe, one of said segments being lxedly connected to the upper end of said innermost section and the other of said segments being releasably connected thereto,

Said segments having arcuate pipe-gripping dies mounted on their inner faces.

CLAUDIE R. TRAHAN.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 656,515 Cassity et al Aug. 21, 1900 1,897,434 Loeber et al Feb. 14, 1933 2.222.207 Teis et al. Nov. 19, 1940 

